Motor driven high stability brake for linear motion systems

ABSTRACT

The present invention relates to a stability brake for absorbing parasitic vibrations of a stage moved to a working position in a motion system. The stability brake includes a motor coupled to a flexure plate through a translation system. The translation system translates horizontal motion of the motor into vertical motion of the flexure plate. The stability brake can be mounted to a stage in a motion system, such as a linear motion system. The stability brake is operative to absorb jitters and vibrations of the stage when the stage is moved to a working position in a motion system and held under servo at the working position.

TECHNICAL FIELD

The present invention generally relates to motion systems and inparticular to a system and method for stabilizing a stage of a linearmotion system during high precision positioning.

BACKGROUND OF THE INVENTION

Typically, linear motion systems comprise one or more tracks or guiderails on which a stage or carriage is moved. The movement can beaccomplished by mechanical, electrical or pneumatic means. The linearmotion systems have gained popularity in the machine tool, semiconductorand medical industries due to the ability of the linear motion system tomove loads in a linear direction to a position with extreme accuracy andat very high speed. However, problems arise with moving a stage to aspecific position with high precision, while holding the position of thestage so that forces acting on the carriage will not move the carriagefrom the desired position. A locking system such as a brake isconventionally employed to hold the position of the stage, butconventional brake devices do not provide stability without highdistortion for very high precision motion, such as that necessary in thesemiconductor industry.

The linear motion system is subjected to noise during normal operation.The noise can be electrical noise, ambient noise, ground noise,transmitted noises from the linear motion systems and other noise thatcause small amounts of jittering or jumping in the stage when the stageis stopped and held in a desired position. These types of jittering andjumping cannot be measured or compensated for utilizing typical feedbackelements of the stage. Furthermore, when a linear motor is utilized tomove the stage, the stage is subjected to a load from the driving of theservo motor or the like. The loaded stage also contributes to thejittering or jumping of the stage when the stage is held in a desiredposition. A conventional brake system includes an actuator coupled to aspring using a fulcrum and lever. However, this type of conventionalbrake system cannot control the amount of jump or jitter of the stage.

Accordingly, it is desirable to provide a system and/or method that canprovide high precision motion with high stability.

SUMMARY OF THE INVENTION

The following presents a simplified summary of the invention in order toprovide a basic understanding of some aspects of the invention. Thissummary is not an extensive overview of the invention. It is intended toneither identify key or critical elements of the invention nor delineatethe scope of the invention. Its sole purpose is to present some conceptsof the invention in a simplified form as a prelude to the more detaileddescription that is presented later.

The present invention relates to a stability brake for a motion systemand a method of producing and using a stability brake. The stabilitybrake includes a motor coupled to a flexure plate through a translationsystem. The translation system translates horizontal motion of the motorinto vertical motion. The translation system translates vertical motioninto a multiple of the horizontal motion. Therefore, a large verticalmovement of the flexure plate can be provided by small horizontalmovement of the motor, such that a translation gain results. Thestability brake can be mounted to a stage in a motion system, such as alinear motion system. The stability brake is operative to absorb jittersand vibrations of the stage when the stage is moved to a workingposition in a motion system and held under servo at the workingposition.

In one aspect of the invention, the translation system is comprised of afirst wedge portion and a second wedge portion. The first wedge portionis coupled to a motor through a movable strip, while the second wedgeportion is coupled to a flexure plate. Horizontal movement of themovable strip by the motor causes horizontal movement of the first wedgeportion which is translated into vertical movement of the second wedgeportion and the flexure plate. The angles of the first and second wedgeportions can be selected to provide different translation ratios (e.g.,10:1, 5:1, 3:1, 2:1), such that movement of the motor translates tomovement of the flexure plate that is a multiple of the movement of themotor. The flexure plate absorbs jittering, vibration and otherparasitic motions of the stage under servo.

The following description and the annexed drawings set forth in detailcertain illustrative aspects of the invention. These aspects areindicative, however, of but a few of the various ways in which theprinciples of the invention may be employed. Other advantages and novelfeatures of the invention will become apparent from the followingdetailed description of the invention when considered in conjunctionwith the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a single axis motion systememploying a high stability brake system in accordance with one aspect ofthe present invention.

FIG. 2 illustrates a perspective view of a multi-axis motion systememploying a high stability brake system in accordance with one aspect ofthe present invention.

FIG. 3 illustrates a cross-sectional view of a stability brake inaccordance with one aspect of the present invention.

FIG. 4 illustrates a cross-sectional view of a stability brake movingfrom a disabled position to an enabled position in accordance with oneaspect of the present invention.

FIG. 5 illustrates a cross-sectional view of a stability brake movingfrom an enabled position to a disabled position in accordance with oneaspect of the present invention.

FIG. 6 illustrates a perspective view of a stability brake having anencoder in accordance with one aspect of the present invention.

FIG. 7 illustrates a flow diagram of a methodology for providing astability brake in accordance with one aspect of the present invention.

FIG. 8 illustrates a flow diagram of a methodology for providing andusing a stability brake with an encoder in accordance with one aspect ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be described with reference to stabilitybrake for a motion system and a method of producing and using the same.The stability brake includes a motor coupled to a flexure plate througha translation system. The translation system translates horizontalmotion of the motor into vertical motion of the flexure plate. Thetranslation system also translates the vertical motion into a multipleof the horizontal motion. That is large vertical movement is provided bysmall horizontal movement of the motor, such that a translation gain(e.g., 10:1, 5:1, 2:1) is provided. The stability brake can be mountedto a stage in a motion system, such as a linear motion system. Thestability brake is operative to absorb jitters and vibrations of thestage when the stage is moved to a working position in a motion systemand held under servo at the working position.

FIG. 1 illustrates a linear motion system 10 having a high stabilitybrake or stabilizer system in accordance with an aspect of the presentinvention. The linear motion system 10 includes a slide or stage 12 witha first stability brake or stabilizer 14 mounted at a first end and asecond stability brake or stabilizer 16 mounted at a second end. Theslide or stage 12 moves along a pair of rails 24 and 25 attached to abase 18. It is to be appreciated that only a portion of the base 18 isshown for illustrative purposes and the base 18 can be comprised of anentire path or track system on which the slide or stage 12 moves. Alinear motor 22 disposed inside the base 18 generates a magnetic fieldto control the positioning, movement and stopping of the stage 12 alongthe base 18. The slide or stage 12 can include a plurality of magnetsdisposed therein. The magnetic field generated by the linear motor 22causes the magnets in the stage 12 to move and stop at a desiredposition along the base 18. A controller (not shown) controls theexcitation of the linear motor 22, which provides precise positioning ofthe slide or stage 12 along the rails 24 and 25.

The stage or slide 12 is moved to a work position with precisioncontrolled by the linear motor 22 and the controller (not shown).However, noise in the system 10 such as ground noise, ambient noise andsystem noise cause small amounts of jittering or vibration of the stage12. These types of jitter or vibration cannot be measured or compensatedfor by typical feedback elements (e.g., encoder) of the stage.Therefore, the present invention employs the first and second stabilitybrake 14 and 16, which engage a first and second wear plate 19 and 20,respectively, upon moving to the work position. The stability brakes 14and 16 allow for the stage 12 to hold position to an order of at least 5nanometers.

In one type of linear motion system, the path or base 12 includes setsof winding, such as repeating phases of a multiphase armature. Thewindings are operative to receive corresponding phases of drive powerproduced by a motor controller. The stage 12 includes a plurality ofmotor magnets arranged, for example, in a generally linear array in adirection of travel. The magnets further are arranged so that adjacentmagnets have alternating polarity so as to interact with the magneticfield generated by the windings, which can produce translational forcesthat effect desired relative movement between the stage and path. It isto be understood and appreciated that, alternatively, the windings couldbe implemented at the stage and the magnets could be arranged in thedirection of travel along the path. It also is to be understood andappreciate that the stabilizer also could be implemented with respectmulti-axis linear and/or rotary actuators in accordance with an aspectof the present invention.

The present invention also is applicable to other types of linear motorsystems, such as a linear stepper motor as well as rotary motors. Alinear stepper motor includes a forcer (or stage) having windings thatare inserted into a laminated core assembly. The stepper also includes astationary platen having a plurality of teeth spaced apart from eachother in a direction of movement to define the path. The forcer moves byapplication of power to a winding, which generates force by causingteeth of the forcer to align with teeth of the platen. The change incurrent through the windings causes the teeth to consecutively alignand, thus, create linear motion. There are various configurations oflinear motors, including generally flat motors, U-channel and tubularshaped motors. Different types of linear motors also are available,including brush, AC brushless, stepper, and induction motors. Common tomost linear motors are a moving assembly, usually called a forcer, whichmoves relative to a stationary platen according to magnetic fieldsgenerated by application of current through one or more associatedwindings. The windings can be on the forcer or at the platen dependingon the type of motor.

It is to be appreciated that the example of FIG. 1 is one particularexample of a motion system employing the high stability brake system inaccordance with the present invention. The present invention is alsoapplicable to mechanical bearing positioning systems, rotary positioningsystems, air bearing positioning systems, ball-screw driven positioningsystems and a variety of different linear motor driven positioningsystems. The present invention is particularly suitable forsemiconductor fabrication, such as deep Ultra-Violet (UV) metrology,electron beam metrology and basic metrology of semiconductor wafers.Although the present examples are illustrated with respect to a linearmotion system, the high stability brake system of the present inventionis applicable to a variety of different motion systems and stages (e.g.,mechanical bearing stages, linear motor stages, rotary stages).

Additionally, the present invention is applicable to multi-axis stagepositioning systems. FIG. 2 illustrates a multi-axis stage positioningsystem 30 having a X-axis path system 31 disposed over a Z-axis pathsystem 41. The X-axis path system 31 and the Z-axis path system 41 areboth similar to the linear motion system 10 illustrated in FIG. 1. Astage 32 is illustrated on the X-axis path 31 moving along a pair ofrails 33 and 34. The stage 32 includes a first stabilizer brake 35 on afirst end and a second stabilizer brake 36 on a second end. The stage 32moves to a working position on the X-axis path and the first stabilizerbrake 35 and the second stabilizer brake 36 are enabled. The first andsecond stabilizer brakes 35 and 36 make contact with a first and asecond wear plate 37 and 38, respectively, to compensate for jitteringof the stage 32 when held in position under servo by a linear motor 39.The Z-axis path also includes a similar stage (not shown) with first andsecond stabilizer brakes that operate in a similar fashion of the firstand second stabilizer brakes 35 and 36 of the X-axis path. Therefore,further discussion of such will be omitted for the sake of brevity. Itis to be appreciated that the present invention is not limited totwo-axis motion system but can be employed in any number of multipleaxis systems (e.g., X-axis, Y-axis and Z-axis systems).

FIG. 3 illustrates a cross-sectional view of an example of a stabilitybrake 50 in accordance with one aspect of the present invention. Thestability brake 50 includes a motor 54, a translation system 60 and aflexure plate 74 residing in a housing 52. The translation system 60translates horizontal movement of the motor 54 into vertical movement ofthe flexure plate 74. Although the motor 54 is illustrated as beingmounted horizontally, a vertically mounted motor configuration can beemployed to carry out the present invention. The flexure plate 74includes a contact protuberance or button 78 on a bottom surface of theflexure plate 74. The stability brake 50 has an enabled position inwhich the contact protuberance or button 78 of the flexure plate 74makes contact with a wear plate 80. The stability brake.50 has adisabled position in which the contact protuberance or button 78 doesnot make contact with the wear plate 80.

The motor 54 controls the state of the stability brake 50 by movingbetween a first horizontal position and a second horizontal position.The motor 54 can be turned off after being moving the stability brake 50to an enabled position. The translation system 60 translates thehorizontal movement of the motor 54 into vertical movement of theflexure plate 74. The translation system 60 includes a first wedgeportion 62 and a second wedge portion 64. The use of a motor drivenstability brake along with a translation system with a first and secondwedge portion gives a higher multiple ratio between movement of themotor and the contact protuberance or button. The angles of the firstand second wedge portions can be selected to provide differenttranslation ratios (e.g., 10:1, 5:1, 3:1, 2:1), such that movement ofthe motor 54 translates to movement of the contact protuberance orbutton 78 that is a multiple of the movement of the motor 54.

In one aspect of the invention, the motor 54 is a piezoceramic linearmotor. A piezoceramic linear motor operates at frequencies much higherthan the mechanical resonance of the stage and allows continuous smoothmotion, while maintaining high resolution and position accuracy typicalof piezoelectric devices. The motor 54 is connected to a strip 56 (e.g.,a ceramic strip) by an attachment piece (not shown). The strip 56 isconnected to a moving part 58. A first bearing assembly 66 is providedbetween the moving part 58 and the first wedge portion 62, while asecond bearing assembly 70 is provided between the first wedge portion62 and the second wedge portion 64. The first and second bearingassemblies 66 and 70 facilitate horizontal movement of the first wedgeportion 62.

A vertical bearing assembly 68 is provided between the second wedgeportion 64 and the housing 52. The vertical bearing assembly 68facilitates vertical movement of the second wedge portion 64. The secondwedge portion 64 has a wedge shaped portion 65 and a long verticalportion 67. The long vertical portion 67 is coupled to the verticalbearing assembly 68, while the wedge shaped portion 65 is coupled to thefirst wedge portion 62 through the second bearing assembly 70. The motor54 moves the moving part 58 horizontally plane causing horizontalmovement of the first wedge portion 62, which translates into verticalmovement of the second wedge portion 64.

The motor 54 has a first position for enabling the stabilizer brake 50and a second position for disabling the stabilizer brake 50. The motor54 moves the strip 56 in a horizontal direction causing the moving part58 to move in a horizontal direction. This causes the first wedgeportion 62 to move along bearing assembly 66 causing downward force onthe second wedge portion 64. The second wedge portion 64 then movesalong second bearing assembly 70 and vertical bearing assembly 68forcing a contact piece 72 into the flexure plate 74. The contact piece72 is disposed between the second wedge portion 64 and the flexure plate74. The flexure plate 74 then moves the contact protuberance or button78 in contact with the wear plate 80 enabling the brake 50. The motor 54can be turned off after being moving the stability brake 50 to anenabled position. The flexure plate 74 includes a plurality of toprecesses 77 and a plurality of bottom recesses 76 that allow the flexureplate 74 to absorb jittering, vibration and other parasitic motions ofthe stage under servo. The flexure plate 74 can be formed of copper,steel or some other metal.

FIGS. 4-5 illustrate movement of a stability brake 90 between an enabledposition and a disabled position in accordance with an aspect of thepresent invention. The stability brake 90 includes a motor 92, atranslation system 110 and a flexure plate 116. The translation system110 translates horizontal movement of the motor 92 into verticalmovement of the flexure plate 116. The flexure plate 116 includes acontact protuberance or button (e.g., spherical) 118 on a bottom surfaceof the flexure plate 116. The translation system 110 includes a firstwedge portion 112 and a second wedge portion 114. The motor 92 isconnected to a strip 96 by an attachment piece (not shown). The strip 96is connected to a moving part 98. The moving part 98 is operativelycoupled to the first wedge portion 112 and moves along a first bearingassembly 95. The first wedge portion 112 is operatively coupled to thesecond wedge portion 114 through a second bearing assembly 113, suchthat horizontal movement of the first wedge portion 112 causes verticalmovement of the second wedge portion 114. The second wedge portion movesvertically along a vertical bearing assembly 111. A contact piece 115 isdisposed between the second wedge portion 114 and the flexure plate 116,so that vertical movement of the contact piece 115 causes verticalmovement of the flexure plate 116 and the contact protuberance or button118.

The motor 92 controls the state of the stability brake 90 by movingbetween a first horizontal position and a second horizontal position.FIG. 4 illustrates movement of the stability brake from a disabledposition to an enabled position. The motor 90 moves the strip 96 and,thus, moves the moving part 98 from a first position to a secondposition in the direction of arrows 100. The moving part 98 moves thefirst wedge portion 112 in the direction of arrow 102 causing downwardforce of the second wedge along arrow 104. The downward force pushescontact piece 115 against the flexure plate 116, which results incontact protuberance 118 being forced in the direction of arrow 106. Thecontact protuberance or button 118 makes contact with a braking surface(not shown). The flexure plate 116 includes a plurality of top recesses91 and bottom recesses 93 which allows the flexure plate 116 to flex andabsorb parasitic movement relating to jittering or vibration of thestage (not shown) and the braking surface (not shown).

FIG. 5 illustrates movement of the stability brake 90 from an enabledposition to a disabled position. The motor 92 moves the strip 96 and,thus, the moving part 98 from the second position to the first positionin the direction of arrow 130. The moving part 98 moves the first wedgeportion 112 in the direction of arrow 132 allowing upward movement ofthe second wedge portion 114 along arrow 134. The contact protuberance118 of the flexure plate 116 is moved upward in the direction of arrow136 causing the contact piece 115 to move upward in the direction ofarrow 134. The contact protuberance or button 118 is removed from makingcontact with the braking surface (not shown). The flexure plate 116flexes back to its original position.

It is to be appreciated that the use of a motor driven stability brakealong with a translation system with a first and second wedge portiongives a higher multiple ratio between movement of the motor and thecontact protuberance. The angles of the first and second wedge portionscan be selected to provide different translation ratios (e.g., 10:1,5:1, 3:1, 2:1), such that movement of the strip 96 translates tomovement of the contact protuberance or button that is a multiple of themovement of the strip. Therefore, precision of movement of the stabilitybrake is improved.

FIG. 6 illustrates a bottom perspective view of a stability brake 140employing an encoder 172 mounted to a translation system 152 for furtherimprovement in precision of the stability brake 140. The stability brake140 includes a motor 144, the translation system 152 and a flexure plate168 residing in a housing 142. The translation system 152 translateshorizontal movement of the motor 144 into vertical movement of theflexure plate 168. The flexure plate 168 includes a contact protuberanceor button 160 on a bottom surface of the flexure plate 168. Thestability brake 140 has an enabled position in which the contactprotuberance or button 160 of the flexure plate 168 makes contact with abraking surface (not shown). The stability brake 140 has a disabledposition in which the contact protuberance 160 does not make contactwith a braking surface (not shown). The motor 144 controls the state ofthe stability brake 140 by moving between a first horizontal positionand a second horizontal position. The translation system 152 translatesthe horizontal movement of the motor 144 into vertical movement of theflexure plate 168. The translation system 152 includes a first wedgeportion 154 and a second wedge portion 156.

The motor 144 is connected to a (not shown) by an attachment piece (notshown). The strip is connected to a moving part 150. A bearing assemblyis provided between the moving part 150 and the first wedge portion 154,while a bearing assembly 164 is provided between the first wedge portion154 and the second wedge portion 156. A contact piece (not shown) isdisposed between the second wedge portion 156 and the flexure plate 168.A vertical bearing assembly 148 is provided between the second wedgeportion 156 and the housing 142. An encoder 172 is connected to thesecond wedge portion 156. The encoder 172 measures positioninginformation of the second wedge portion 156 using a scale or tape 153having a plurality of markings. The scale 153 resides on a verticalportion of the second wedge portion 156. In one aspect of the invention,the scale 153 is a ¼-inch wide metal tape piece. The encoder 172 iselectrically coupled to the motor 144 and provides the motor 144 withpositioning information so that the motor can provide absolutepositioning of the motor 144, strip 146, moving part 150 and first wedgeportion 154.

The motor 144 has a first position for enabling the stabilizer brake 140and a second position for disabling the stabilizer brake 140. The motor140 illustrated in FIG. 6 is a two finger motor type, however, it is tobe appreciated that other motor types can be employed to carry out thepresent invention. The motor 144 moves the strip in a horizontaldirection causing the moving part 150 to move in a horizontal direction.This causes the first wedge portion 154 to move along bearings 162causing downward force on the second wedge portion 156. The second wedgeportion 156 then moves along bearings 164 and vertical bearings 148forcing the flexure plate 168 vertically by the contact piece. Theflexure plate 168 then moves the contact protuberance or button 160 incontact with a braking surface enabling the brake 140. The flexure plate168 includes a plurality of recesses 166 and 167 that allow the flexureplate 168 to absorb jittering, vibration and other parasitic motions ofthe stage (not shown) under servo. The encoder 172 measures positioninginformation of the second wedge portion 156 and provides thisinformation to the motor 144, so that the motor can make appropriatepositioning adjustments.

In view of the foregoing structural and functional features describedabove, methodologies in accordance with various aspects of the presentinvention will be better appreciated with reference to FIGS. 7-8. While,for purposes of simplicity of explanation, the methodologies of FIGS.7-8 are shown and described as executing serially, it is to beunderstood and appreciated that the present invention is not limited bythe illustrated order, as some aspects could, in accordance with thepresent invention, occur in different orders and/or concurrently withother aspects from that shown and described herein. Moreover, not allillustrated features may be required to implement a methodology inaccordance with an aspect the present invention.

FIG. 7 illustrates one particular methodology for providing a stabilitybrake in accordance with one particular aspect of the present invention.The methodology begins at 200 with providing a translation system fortranslating horizontal movement to vertical movement. For example, thetranslation system can be comprised of a first and second wedge portionto provide a translation ratio based on the angle of the first andsecond wedge portion. At 210, a moving part is coupled to a motor forproviding horizontal movement. The moving part can be coupled directlyto the motor or through a strip. The motor can be a piezoceramic linearmotor and the strip can be a ceramic strip, such that precision can beprovided in the nanometers. At 220, the moving part is coupled to thetranslation system through a bearing assembly or the like.

At 230, a flexure plate is then coupled to a translation system forproviding vertical movement of the stability brake. The flexure plate isoperative to absorb vibration, jittering and other noise associated witha stage of a motion system. The flexure plate can be provided with oneor more recesses to allow the flexure plate to absorb parasitic motionassociated with vibrations of a stage under servo. At 240, a contact isprovided on the flexure plate for making contact with a braking surface.The contact can be spherically shaped. An encoder is then mechanicallyattached to the translation system and electrically attached to themotor for providing positioning information relative to the flexureplate to the motor at 250. The encoder can use a scale such as amechanical tape with markings to measure positioning informationrelative to vertical movement of the flexure plate. At 260, thestability brake is attached to a stage and the stage provided in amotion system.

FIG. 8 illustrates one particular methodology for stabilizing a stageusing a stability brake in accordance with one particular aspect of thepresent invention. The methodology begins at 300 with providing a motorcoupled to a first wedge portion through a moving strip. At 310, aflexure plate is coupled to a second wedge portion via a contact piece.The angles of the first and second wedge portions can be selected toprovide different translation ratios (e.g., 10:1, 5:1, 3:1, 2:1), suchthat movement of the motor translates to movement of the flexure platethat is a multiple of the movement of the motor. The flexure plate isoperative to absorb jittering, vibration and other parasitic motions ofa stage under servo. At 320, an encoder is mechanically coupled to thesecond wedge and electrically connected to the motor. The first wedge isthen coupled to the second wedge via bearings or the like at 330.

At 340, the first wedge is moved in a horizontal direction by moving themotor to a first position. At 350, the second wedge and the flexureplate move in a vertical direction in response to horizontal movement ofthe first wedge. At 360, position information of the second wedge ismeasured and provided to the motor. The motor then adjusts the positionof the first wedge based on the position information of the second wedgeat 370. At 380, the first wedge, the second wedge and the moving plateare moved to their original position by moving the motor to a secondposition.

What has been described above are examples of the present invention. Itis, of course, not possible to describe every conceivable combination ofcomponents or methodologies for purposes of describing the presentinvention, but one of ordinary skill in the art will recognize that manyfurther combinations and permutations of the present invention arepossible. Accordingly, the present invention is intended to embrace allsuch alterations, modifications and variations that fall within thespirit and scope of the appended claims.

What is claimed is:
 1. A linear motion system comprising: a stageoperative to move along path to a working position; and a stabilitybrake mounted to the stage, the stability brake having a motor coupledto a flexure plate through a translation system, the translation systemtranslates horizontal movement of the motor to vertical movement of theflexure plate, such that the flexure plate makes contact with a surfaceof the path to absorb vibration of the stage in the working position. 2.The system of claim 1, the linear motion system being a single axissystem.
 3. The system of claim 1, the linear motion system being amulti-axis system.
 4. The system of claim 1, the stability brake beingmounted to a first end of the stage and a second stability brake beingmounted to a second end of the stage.
 5. The system of claim 1, thetranslation system comprising a first wedge portion coupled to the motorand a second wedge portion coupled to the flexure plate, such thathorizontal movement of the first wedge portion causes vertical movementof the second wedge portion and the flexure plate.
 6. The system ofclaim 5, the first wedge portion and the second wedge portion having anangle that is selected to provide a translation ratio that is thevertical movement of the flexure plate over the horizontal movement ofthe motor.
 7. The system of claim 6, the translation ration being one of10:1, 5:1, 3:1 and 2:1.
 8. The system of claim 1, the flexure platehaving a plurality of recesses for allowing the flexure plate to absorbvibration of the stage in the working position.
 9. The system of claim1, the flexure plate having a contact protuberance on the surface of theflexure plate, the contact protuberance operative to make contact with asurface of the path to absorb vibration of the stage in the workingposition.
 10. The system of claim 1, further comprising an encodermounted to the translation system, the encoder determines the verticalmovement of the flexure plate and provides adjustment information to themotor.
 11. A stability brake for absorbing parasitic motion of a stageheld in a working position on a motion system, the stability brakecomprising: a motor; a flexure plate operative to make contact with asurface of motion system to absorb vibration of a stage in the workingposition; and a translation system that translates horizontal movementof the motor into vertical movement of the flexure plate.
 12. Thestability brake of claim 11, the translation system comprising a firstwedge portion coupled to the motor and a second wedge portion coupled tothe flexure plate, such that horizontal movement of the first wedgeportion causes vertical movement of the second wedge portion and theflexure plate.
 13. The stability brake of claim 12, the first wedgeportion and the second wedge portion having an angle that is selected toprovide a translation ratio, the translation ratio being the verticalmovement of the flexure plate over the horizontal movement of the motor.14. The stability brake of claim 13, the translation ration being one of10:1, 5:1, 3:1 and 2:1.
 15. The stability brake of claim 12, the secondwedge portion having a wedge shaped portion and a long vertical portion,the long vertical portion moving vertically along a vertical bearingassembly.
 16. The stability brake of claim 15, further comprising anencoder mounted to the long vertical portion, the encoder determines thevertical movement of the long vertical portion and provides adjustmentinformation to the motor.
 17. The stability brake of claim 16, furthercomprising a scale provided on the long vertical portion, the scalehaving a plurality of markings used by the encoder to determine thevertical movement of the long vertical portion.
 18. The stability brakeof claim 11, the flexure plate having a plurality of recesses forallowing the flexure plate to absorb vibration of the stage in theworking position.
 19. The stability brake of claim 11, the flexure platehaving a contact protuberance on the surface of the flexure plate, thecontact protuberance being operative to make contact with a surface of apath to absorb vibration of a stage in a working position.
 20. Thestability brake of claim 11, the motor being a piezoceramic linearmotor.
 21. A method for providing a stability brake for absorbingparasitic motion of a stage held in a working position on a motionsystem, the method comprising: providing a translation system thattranslates horizontal movement into vertical movement; coupling a motorto the translation system for providing horizontal movement; andcoupling a flexure plate to the translation system, the flexure plateoperative to absorb parasitic motion of a stage held in a workingposition.
 22. The method of claim 21, further comprising providing theflexure plate with a contact protuberance operative to make contact witha surface of the motion system.
 23. The method of claim 21, furthercomprising providing the flexure plate with a plurality of recesses thatallow the flexure plate to absorb parasitic motion.
 24. The method ofclaim 21, the translation system comprising a first wedge portioncoupled to the motor and a second wedge portion coupled to the flexureplate, such that horizontal movement of the first wedge portion causesvertical movement of the second wedge portion and the flexure plate. 25.The method of claim 21, further comprising attaching an encoder to thetranslation system, the encoder determining the vertical movement of theflexure plate and providing adjustment information to the motor.
 26. Astability brake for absorbing parasitic motion of a stage held in aworking position on a motion system, the stability brake comprising:means for absorbing vibration of a stage in a working position; meansfor providing horizontal movement; means for translating the horizontalmovement into vertical movement of the means for absorbing vibration ofa stage in the working position, such that horizontal movement between afirst position and a second position moves the stability brake between adisabled position and an enabled position.
 27. The system of claim 26,further comprising means for determining the vertical movement of themeans for absorbing vibration of a stage in a working position.